It is common knowledge that there are numerous errors in the delivery of fuel oil to the consumer resulting in a substantial financial loss, particularly so now that the price of petroleum products has substantially increased. The common source of these errors is to switch pumping fuel from one compartment of the delivery truck to an empty compartment wherein through continued angular momentum there is false register of a liquid flow.
In prior art flowmeters, the inaccuracy in most of the meters, revolve around the angular momentum of the rotating shaft. The angular momentum of the rotating shaft causes the meter to register even after the liquid has ceased to flow. The prior art flowmeters were also difficult to mount and often required special mounting features. In addition, errors in the true amount of liquid flow were introduced by perturbations in the liquid emanating from eddy currents at the pipe wall and within the conduit itself. This is so in one sense since the velocity of the fluid passing along the walls of the pipe is significantly lower than the velocity passing in the center, a non-linear measurement resulted due to changing flow rates.
In U.S. Pat. No. 3,686,947, granted Aug. 29, 1972, to Maeshba, there is disclosed a liquid measuring device wherein moving vanes are disposed within a U-shaped conduit. Such device required special mounting and was subject to errors in liquid volumetric measurements as aforesaid.
The present invention in one aspect seeks to resolve the problem of angular momentum. First, the rotating shaft and vane are placed in the substantially vertical portion of a U-shaped pipe, on the outlet side. In this manner, liquid will always be surrounding the turbine vane and necessarily dampens the spinning of the vane when the flow of the liquid ceases. Additionally, the present invention seeks to reduce the angular momentum by limiting the radial size and mass of the transducer.
Additional sources of error in the prior art were due to magnetic switching being error prone at different flow rates.
Therefore, it is an object of the present invention to provide a liquid volumetric measuring apparatus which substantially obviates one or more of the aforesaid limitations and disadvantages in the prior art.
It is a principal object of this invention to provide a liquid volumetric flowmeter wherein the liquid flow is accurately measured while precluding false measurement of the gaseous flow.
It is another object of the invention to provide an apparatus as aforesaid wherein the liquid is accurately measured, which apparatus is of an integral construction.
It is another object of the invention to provide a liquid volumetric flowmeter as aforesaid which need not be calibrated for each different trap in which it is to be installed.
It is another object of the present invention to provide the consumer with a method to inexpensively verify the amount of fuel that was allegedly pumped into his tank.
It is a further object of the present invention to provide a liquid volumetric measuring apparatus, having motive flow detecting elements continuously immersed in the liquid to be measured, and prevent erroneous measurements by prohibiting the measurement of air flow, and wherein the measuring elements are stopped upon the cessation of the flow of liquid through the trap.
It is a further object of the present invention to provide a magnetic sender which operates accurately at low and high flow rates.
It is still a further object of the present invention to provide an electrical means of calculating the volumetric flow with a high degree of accuracy at a relatively low cost of manufacture.
It is still a further object of the present invention to provide a novel battery status indicator.